The present invention relates to thiadiazoles and, more particularly to amide derivatives of 1,3,4-thiadiazoles having a halogenated alkyl group in the 5-position. It is known in the art that various types of thiadiazole compositions may be used for pesticidal purposes. For example, Belgian Pat. No. 721,034 teaches that certain compounds, only generally related to that taught in the present invention, have herbicidal properties. However, the particular compounds of the present invention are believed to have biological activity which has heretobefore not known nor anticipated.